<template>
  <!--使用下拉树形-->
  <!--例子-->
  <!--<cai-tree-select v-model="formData.org_id" filterable :data="org_idOption"></cai-tree-select>-->
  <!--org_idOption=[{id:21,parentid:'',level:1,date:'2023-10-24 15:05:50',name:'111',address:'',children:[]}]-->
  <el-select
      :title="multiple? optionData.name : ''"
      ref="select"
      :value="value"
      placeholder="请选择"
      clearable
      :disabled="disabled"
      :filterable="filterable"
      :filter-method="filterMethod"
      style="width: 100%;"
      @clear="clear"
      @visible-change="visibleChange"
  >
    <el-option
        ref="option"
        class="tree-select__option"
        :value="optionData.id"
        :label="optionData.name"
    >
      <el-tree
          ref="tree"
          class="tree-select__tree"
          :class="`tree-select__tree--${multiple ? 'checked' : 'radio'}`"
          :node-key="nodeKey"
          :data="data"
          :props="props"
          :default-expanded-keys="[value]"
          :show-checkbox="multiple"
          :highlight-current="!multiple"
          :expand-on-click-node="multiple"
          :filter-node-method="filterNode"
          @node-click="handleNodeClick"
          @check-change="handleCheckChange"
      ></el-tree>
    </el-option>
  </el-select>
</template>

<script>
export default {
  name: 'TreeSelect',
  props: {
    // v-model绑定
    value: {
      type: [String, Number],
      default: ''
    },
    multiple: {
      type: Boolean,
      default: false
    },
    // 树形的数据
    data: {
      type: Array,
      default: function () {
        return []
      }
    },
    // 每个树节点用来作为唯一标识的属性
    nodeKey: {
      type: [String, Number],
      default: 'id'
    },
    filterable: {
      type: Boolean,
      default: false
    },
    disabled: {
      type: Boolean,
      default: false
    },
    // tree的props配置
    props: {
      type: Object,
      default: function () {
        return {
          label: 'name',
          children: 'children'
        }
      }
    }
  },
  data() {
    return {
      optionData: {
        id: '',
        name: ''
      },
      filterFlag: false
    }
  },
  watch: {
    value: {
      handler(val) {
        if (!this.isEmpty(this.data)) {
          this.init(val)
        }
      },
      immediate: true
    },
    data: function (val) {
      if (!this.isEmpty(val)) {
        this.init(this.value)
      }
    }
  },
  created() {
  },
  methods: {
    // 是否为空
    isEmpty(val) {
      for (let key in val) {
        return false
      }
      return true
    },
    handleNodeClick(data) {
      if (this.multiple) {
        return
      }
      this.$emit('input', data[this.nodeKey])
      this.$refs.select.visible = false
    },
    handleCheckChange() {
      const nodes = this.$refs.tree.getCheckedNodes()
      const value = nodes.map((item) => item[this.nodeKey]).join(',')
      this.$emit('input', value)
    },
    init(val) {
      // 多选
      if (this.multiple) {
        const arr = val.toString().split(',')
        this.$nextTick(() => {
          this.$refs.tree.setCheckedKeys(arr)
          const nodes = this.$refs.tree.getCheckedNodes()
          this.optionData.id = val
          this.optionData.name = nodes
              .map((item) => item[this.props.label])
              .join(',')
        })
      }
      // 单选
      else {
        val = val === '' ? null : val
        this.$nextTick(() => {
          this.$refs.tree.setCurrentKey(val)
          if (val === null) {
            return
          }
          const node = this.$refs.tree.getNode(val)
          this.optionData.id = val
          this.optionData.name = node.label
        })
      }
    },
    visibleChange(e) {
      if (e) {
        const tree = this.$refs.tree
        this.filterFlag && tree.filter('')
        this.filterFlag = false
        let selectDom = null
        if (this.multiple) {
          selectDom = tree.$el.querySelector('.el-tree-node.is-checked')
        } else {
          selectDom = tree.$el.querySelector('.is-current')
        }
        setTimeout(() => {
          this.$refs.select.scrollToOption({$el: selectDom})
        }, 0)
      }
    },
    clear() {
      this.$emit('input', '')
    },
    filterMethod(val) {
      this.filterFlag = true
      this.$refs.tree.filter(val)
    },
    filterNode(value, data) {
      if (!value) return true
      const label = this.props.label || 'name'
      return data[label].indexOf(value) !== -1
    }
  }
}
</script>

<style lang="scss">
.tree-select__option {
  &.el-select-dropdown__item {
    height: auto;
    line-height: 1;
    padding: 0;
    background-color: #fff;
  }
}

.tree-select__tree {
  padding: 4px 20px;
  font-weight: 400;

  &.tree-select__tree--radio {
    .el-tree-node.is-current > .el-tree-node__content {
      color:#409eff;
      font-weight: 700;
    }
  }
}
</style>
